I tried mapping a few buildings having surveyed them manually. When entering them into JOSM, they are clearly rectangular but in the mapnik rendering, they come out slightly diamond shaped. I used the orthoganalize tool and even going back and rotating them to point due North, they are clearly rectangular in JOSM. Any idea what’s going on and how to avoid this.
Is this perhaps due to the map projection used by mapnik? I would have thought that as you get further from the equator, the scale would get gradually larger but the shape of objects would be preserved: the X scale and Y scale would remain the same.
You can see the buildings in question here: